Apparatus for moving an ornament and drive means therefor

ABSTRACT

The invention provides in a first aspect a novel synchronous motor in which the rotor comprises a substantially solid multi-pole magnet axially displaced from the coil which, itself, is of substantially the same diametrical size. With this arrangement a very powerful motor can be provided for a relatively small size and is suitable for use in powering ornaments such as Christmas tree ornaments direct from a socket of a fairy light string or decorative lights. In a second aspect of the invention, reciprocation means are provided suitable for use with the synchronous motor of the first aspect which can automatically raise and lower ornaments and similar novelty items. In a third aspect of the invention reciprocation means is provided which may be used either with the synchronous motor of the invention or with a conventional D.C. motor to provide for winding and sudden unwinding of a cord and hence an ornament or a novelty item attached thereto.

This invention relates to apparatus for moving an ornament such as anornament for a Christmas tree or a practical joke novelty item wheremovement is necessary to achieve a desired effect, and for means fordriving such ornament.

Drive means for such ornaments necessarily have to be small and compact,particularly where the ornament has to hang from something, such as abranch of a Christmas tree.

BACKGROUND OF THE INVENTION

There has been proposed in U.S. Pat. No. 4,980,608 an electric motorrotator for Christmas tree ornaments which includes a small-sizesynchronous electric motor which is adapted to plug into a lamp socketof a string-set of series connective decorative incandescent lamps so asto utilize the output of the motor to rotate ornaments and lightdevices.

The motor includes a cup-shaped rotor having an annular magnetic mediumdeposited on the inner wall of the cup on either side of which inner andouter stators are disposed which interact electrically with a small ACexcited coil to cause the rotor to rotate at the synchronous frequency.Even through such a design of motor would, once started, run in onedirection or the other this is no particular problem because it is asimple matter to include a so-called "no-back" device to cause the motorto run in a predetermined direction each time it is energised as isshown, for example, in FIG. 5 of U.S. Pat. No. 4,980,608.

The disadvantage of the motor rotator disclosed in U.S. Pat. No.4,980,608 is that it is of very low power which limits the range ofmovement which can be achieved utilising the device. This is because thecoil is relatively small and magnetic medium is deposited on the innerwall of a cup-shaped rotor such that rotor density is low. Anotherdisadvantage is that a lightweight rotor is, by definition, notparticularly rugged and there is the possibility that damage may occurto the motor in the event that the novelty item were to fall.

It is an object of the invention to provide an apparatus for moving anobject which alleviates this disadvantage.

The present invention is derived from the surprising realisation that ifa large, solid magnetic rotor is provided which is cooperable withelectrically energised and relatively long stators then acorrespondingly large coil may be used even if it is axially displacedrelative to the rotor and, with such construction, the combinationprovides greatly increased power relative to the motor described in U.S.Pat. No. 4,980,608 for the same diametric size.

SUMMARY OF THE INVENTION

According to the invention in its first aspect there is provided asynchronous motor comprising a coil; a rotor mounted co-axially with,but displaced relative to the coil, the rotor comprising a substantiallysolid, cylindrical magnet means; and stator means electricallyassociated with the coil and disposed about the radial periphery of saidrotor for interacting electrically with the rotor to produce rotationalmovement.

With the motor of the invention, the rotor comprises a substantiallysolid cylindrical magnet, thus allowing a substantially larger magneticreaction force to be generated, so increasing the potential power to theweight/size of the motor. As well, the coil may be of the same diameteras the rotor so that the combination of coil and rotor result in a motorof high power which may be used to move relatively heavy novelty itemswhich would not be possible with the prior art motor.

Preferably, the stator means comprises first and second statorsoperatively associated with the opposed axial ends of the coil, onestator means being electrically connected to a casing of the motorcontaining the coil and extending from one end of the coil towards therotor, with the second stator means being disposed at the opposed end ofthe coil and interposed between the limbs of the first stator.

The electric motor is preferably used in an application as an ornamentor other novelty item mover in which the features of small size combinedwith relatively high power are desirable. In this context the term"ornament" used herein is intended to be broadly interpreted to include,for example, replica spiders and other such novelty items where the mainpurpose of the motor is to provide a desired effect in terms of movementof the ornament.

In accordance with a second aspect of the invention, there is providedan ornament mover comprising an ornament movement reciprocation meansincluding a synchronous motor connected to a pulley mechanism havingreaction means for stalling the motor at a point in the path ofreciprocation.

This aspect of the invention provides a means for reciprocating movementof an ornament, up or down for example, in a very simple construction.Specifically, as synchronous motors have no preferred direction ofrotation, they can be incorporated very efficiently into a reciprocatingdesign by providing a pulley mechanism having reaction means forstalling the motor at one point in the path of reciprocating travel ofthe ornament. Since the motor can no longer rotate in its existingdirection due to the action of the reaction member, it will reverserotation thus changing the direction of the pulley mechanism until thereaction means is engaged again to change the direction a further timeand so on.

Preferably, the pulley mechanism includes gearing means powered by themotor to wind a cord to which the ornament is connected onto a pulleydrum, to a retracted position in which the reaction member abuts againstthe casing of the apparatus causing the synchronous motor to stall, thereaction forces between rotor and stator then causing the motor toreverse direction, thus unwinding the cord from the drum. In theextended position when the cord is unwound from the drum, the cord willsimply wind up the other way on the drum to the retracted position.

The ornament mover is preferably used together with the electric motorof the first aspect of the invention.

In accordance with a third aspect of the invention there is provided anornament or other novelty item mover suitable for use with thesynchronous motor of the present invention, if a "no-back" mechanism isincorporated, or with a conventional DC motor if not.

According to the third aspect of the invention there is provided anornament mover comprising a housing, motor means associated with thehousing, a pulley drum drivingly connected to the motor means, a cordattached at one end to the drum and at its other end to an ornament tobe carried thereby, the cord being windable onto the drum by the motormeans, switch means for guidingly receiving the cord and being movablebetween a first position in which the cord can be wound onto the drumand a second position in which the cord is moved axially relative to therotational axis of the drum so that in such position it can becomesuddenly fully unwound therefrom, and control circuit means fordetermining when the switch means is to move from its first position toits second position, thereby to selectively provide winding and suddenunwinding of the cord and consequent corresponding movement of anornament attached thereto.

Preferably, the control means includes an electronic circuit coupled toa motion detector, such as a photo-diode, which operates as a motiondetector such that on a change of light level being received by thephoto detector the control means may switch on or switch off the motormeans to thereby selectively provide for winding or unwinding of thecord and thus the ornament carried thereby onto or off the drum.

With the arrangement of the third aspect of the present invention it istherefore possible to provide an ornament mover wherein, for example,the ornament is a realistic-looking toy insect such as a spider which isthus able to drop down via its attachment to the cord when the latter isunwound from the winding drum in response to movement of the switchmeans from its first position in which it permits the winding of thecord onto the drum and its second position in which it permits the cordto suddenly unwind itself completely. Hence in this third aspect of thepresent invention the apparatus can mimic the movement of a real spideror similar kind of insect upon which there is attached a thread ofweb-like material and upon the approach of a person the "spider"suddenly drops down in front and immediately appears to climb back upits "thread" to the ceiling.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of exampleonly with reference to the accompanying drawings in which;

FIG. 1 is a perspective view of ornament moving apparatus utilizing themotor of the first embodiment of the invention.

FIG. 2 is a cross-sectional view through the motor and transmissionhousing of the embodiment of FIG. 1.

FIG. 3 is an exploded perspective view of a synchronous motor being thesecond embodiment of the invention.

FIG. 4 is a side view of the assembled motor of FIG. 3.

FIG. 5 is a cross-sectional view across A--A of FIG. 4.

FIG. 6A is a side view of the magnet of the rotor of the embodiments ofFIGS. 3-5; and

FIG. 6B being a view in the direction of arrow B of FIG. 6A.

FIG. 7A is a sectional view of an ornament mover in accordance with thethird aspect of the present invention showing the switch means in itsfirst position,

FIG. 7B is a view similar to that of FIG. 7A but showing the switchmeans in its second position and,

FIG. 7C is a corresponding view showing the switch means having returnedto its first position but with the cord having become unwound from thedrum,

FIG. 8 is a simplified circuit diagram illustrating the control meansnecessary to operate the apparatus of FIGS. 7A-C.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference to the drawings, an embodiment of an electric motorChristmas tree ornament moving apparatus is shown generally in FIG. 1and in more detail in FIG. 2. It comprises a motor 1, gear transmissionshown generally at 2 and pulley mechanism shown generally at 3 containedwithin a general tubular plastic housing 4. The housing 4 is providedwith a first hook 5 at one end for connection to a branch 6 of aChristmas tree, or other hanging support, for example a curtain rail.The pulley mechanism 3 is provided at its distal end with a further hook7 to which an ornament 8, for example a Christmas tree ornament, ishung.

With specific reference to FIG. 2, motor 1 is connected by power lines(not shown) to a mains supply of alternating current which, for example,may be by means of a plug which connects directly into the socket of aChristmas tree light set, by replacement of one "fairy" light bulb. Themotor 1 is a synchronous motor driven at a frequency related to the linefrequency of the input alternating current (50/60 hz, generally). Theoutput from the motor 1 is provided by a toothed output shaft 9 whichmeshes with a first spur gear 10 mounted for rotation upon a spindle 11secured to part of the housing 4. Spur gear 10 is itself attached to atoothed shaft 12 which meshes with a second spur gear 13 to which isalso attached a toothed shaft 14. A third spur gear 15 completes thespeed reduction gear train. Third spur gear 15 is itself drivinglyconnected to a bevel gear 16 which in turn meshes with a correspondingbevel gear 17 mounted for rotation on a shaft 18 upon which a pulleydrum 19 is also mounted. A cord 20 is connected at one end to the pulleydrum 19 and at its other end to a spherical stop member 21 to which hook7 is attached.

Housing 4 encloses the motor 1, transmission 2, and pulley mechanism 3and has a circular opening 22 through which cord 20 protrudes. Thediameter of opening 22 is less than that of stop member 21.

In use, when mains power is applied to synchronous motor 1, this willcause the motor to rotate in one rotational direction or the other. Thiswill in turn cause pulley drum 19 to rotate thus paying out or drawingin cord 20. If cord 20 is drawn in to a retracted position, the motorwill continue to rotate until stop member 21 abuts against opening 22.At this point, synchronous motor 1 will stall and, due to the propertyof the synchronous motor which allows omnidirectional rotation, themotor will then change direction to that offering less resistance tomotion, thus paying out cord 20 to an extended position. Once payed outto its fullest extent, the cord 20 will then start re-winding onto drum19 to thus wind cord 20 in to the retracted position and so on, thuscausing ornament 8 to move up and down continuously.

It will be appreciated by one skilled in the art that a synchronousmotor is capable of rotating in one direction or the other and generallywill have no preferred direction of rotation, this being determinedinitially by the relative position of the stator and rotor and theresistance to motion in any particular direction. When stop member 21abuts opening 22, the reaction forces between rotor and stator willcause rotation in the reverse direction since the motor can no longerrotate in its existing direction.

For a synchronous motor to work in the present application, it isessential for it to have sufficient power to raise and lower theornament via the transmission 2. Preferably, the motor 1 should be assmall as possible so that the size of the casing 4 is correspondinglysmall and unobtrusive to the eye.

An embodiment of a preferred motor according of the invention for usewith the ornament mover as described will now be described, by way ofexample only, with reference to FIGS. 3-6.

An exploded view of the motor is shown in FIG. 3 and this comprises acylindrical steel casing 23 closed at one end and having four axialprojections 24, 25, 26 and 27 which form stator poles as describedhereinafter. A coil 28 wound on a hollow cylindrical bobbin 29 isnormally disposed within casing 23 and receives a steel core 30. Core 30is provided with a central cylindrical opening 31 which acts as abearing surface for a shaft 32. A second stator 33 formed with a steelbase 34 has four projections 35, 36, 37 and 38 is connected to end 39 ofcore 30. A magnet rotor 40 having gear 9 connected thereto is mountedfor rotation on shaft 32.

When assembled, the coil 28 lies in the casing 23 with the core 30 beingreceived in the bobbin 29. Second stator 33 is supported on core 30 sothat projections 35-38 and projections 24-27 of casing 23 are co-radialrelative to shaft 32, with rotor 40 being surrounded by the projectionsat its radial periphery, as shown in FIGS. 4 and 5.

The construction of the motor magnet 40 is shown in more detail in FIGS.6A & 6B. The magnet comprises an eight pole ferrite magnet in the shapeof a substantially solid cylindrical disc having only a small centralhole for receiving shaft 32. The poles of the magnet 40 are aligned headto tail around the circumference with like poles being positioneddiametrically opposite to each other.

The pole pieces 24-27 and 35-38 provide stator poles which surround themagnetic rotor 40. The poles 24-27, connected to the casing 23, areexcited by the winding with the opposite polarity to those pole pieces35-38 of the second stator 33. The magnetic polarity and flux changesbetween the two sets of poles at the line frequency. Poles 36, 38 areformed wider than the other poles so as to set up an uneven fluxconcentration facilitating start up rotation when the motor is firstpowered on.

At a particular cycle of energizing current, the stator poles 35-37 willbe at, for example, South polarity while the stator poles 24-27 will beat North polarity. The magnet will be forced to move and align itself sothat its North poles align themselves with the stator poles 35-37 whichare South and the South poles of the magnet align with stator poles24-27 which are North. A half current cycle later, this reverses forcingthe magnet to align itself with the opposite poles. The momentum of therotating magnet at this point carries the motion on linearly in the samerotational direction so as to clear the poles just as the currentdirection changes, causing continuous motion in the manner of any normalsynchronous motor.

A substantial advantage of the motor as described is that it utilisesthe largest possible magnet for a given motor diameter, since the magnetis practically the entire diameter of the motor, apart from the casing,and with the coil being positioned axially spaced apart from the rotoritself. Furthermore, by using a solid core a very efficient means ofconcentrating the inner core's magnetic flux is established.

Turning now to a third aspect of the present invention the arrangementshown in FIGS. 7A-7C and in FIG. 8 illustrate a simple but effectivemotor driven ornament mover which may be used in novelty items such asthose mimicking the falling of a spider from a ceiling or, if preferred,the rising from a floor of other kinds of novelty ornaments, such as toyghosts, which are required to rise a distance before suddenly fallingback to ground level, apparently without any cause.

In FIGS. 7A-7C there is shown in cross-section an ornament mover inaccordance with the invention which includes a rigid base plate 41 ontowhich is mounted a DC-driven motor 42 (or, if preferred, a synchronousmotor of the present invention with a "no-back" device attachedthereto), the motor output shaft again being connected to aspeed-reduction and direction change gear box shown generally at 43 fordriving a spur gear 44 mounted on a drive shaft 45 which extends throughthe base plate 41 and onto the lower end of which is mounted acylindrical pulley drum 46. The pulley drum 46 is therefore rotatablehorizontally about a vertical axis and, in the position shown, isadapted for clockwise rotation. Attached to the pulley drum 46 is a cord47, on the other end of which is a plastics imitation spider 48 whichcan mimic the movement of a real spider in a manner to be described.

Switch means shown generally at 49 are fixed to the base plate 41 andcomprise a hollow housing 50 within which is received an electricalcontact shaft 51 biased by means of a spring 52 to press against anotherelectrical contact 53. At the other end of contact shaft 51 there is aring 54 through which is threaded the cord 47 and which is thenguidingly received by a fixed second ring 55 positioned above a circularopening 56 in a cover 57 fixed to the base plate 41, in any conventionalmanner. Because the toy spider 48 is larger than the opening 56 then itacts as a stop member for the cord 47 in a manner analogous to thespherical stop member 21 shown in FIG. 2. A photo-diode 58 is mountedbetween the cover 57 and the base plate 41.

In the position shown in FIG. 7A the spider has reached its upward limitof travel but the switch control means 49 is still in its closedposition.

In FIG. 7B it will be seen that although the spider 48 is in the sameposition as that shown in FIG. 7A nevertheless the pulley drum 46 hascontinued to wind the cord 47 onto it, thus pulling the ring 54 andhence the contact shaft 51 angularly downwards. At this point the switchmeans 49 becomes de-activated and, in a manner to be described withparticular reference to FIG. 8, the motor 42 then stops. At this stagethe ornament mover is "set" i.e. it is ready for use.

In FIG. 7C, there is shown the next stage of operation in which themotor 42 has been once again activated, the drum 46 has been rotatedeven further to the point where the ring 54 has been pulled furtherdownwards until the last portion of the cord wound onto the drum 46suddenly slips off the drum 46, the spider 48 falls, the ring 54 isreturned via its spring 52 bias back to the position shown in FIG. 7Abut, importantly, the whole of the cord 47 unwinds completely off thedrum 46.

Turning now to FIG. 8 there is shown in schematic detail the circuitarrangement by which the steps described in FIG. 7A-C can occur. Thephoto-diode 58 is connected to conventional motion detector circuitry 59capable of operating a motor controller switch 60 which is normally openbut which can be closed for a short period, such as 3 seconds, when thedetector-diode 58 detects a change of light level. A conventionalbattery 61 is used to power the circuit in a manner which will now bedescribed.

When the ornament mover is in its operating position, perhaps fixed tothe ceiling or hanging by a string attachment from a door lintel etc.,the switch control means 49 is initially in its closed position so thatthe motor 42 is powered by the battery 61 up to the point shown in FIG.7B where the switch means 49 becomes electrically disconnected and themotor thereafter stops. In this position, provided the detector-diode 58remains stable in terms of light input the ornament mover remainsdormant. When a change in light level is detected as a result of,typically, a person walking underneath the detector-diode 58 the motiondetector circuitry 59 activates the switch 60 by closing it for a shortperiod. When this happens the battery can then again power the motor 42so that it continues to wind the cord 47 onto the drum until thesituation shown in FIG. 7C has occurred i.e. the cord 47 slips off thedrum and becomes completely unwound. When this happens the switch means49 becomes closed so that the motor 42 continues to be powered by thebattery 61 even though, shortly thereafter, the motion detector circuits59 opens the switch 60.

The effect of this is that the spider appears to fall and thenimmediately starts to climb back up its "web", being the cord 47, untilit reaches its dormant position and the ornament mover is ready for itsnext "victim".

In an alternative embodiment of the third aspect of the invention thereverse happens. Here, the idea is that the ornament mover is used tolift a novelty item such as a toy ghost once the photo-diode detects thepresence of a person and as soon as it has risen to a predeterminedheight to let the ghost novelty item suddenly drop back to the floor. Inthis embodiment (not illustrated) the dormant phase is when the ghostnovelty item is on the floor and once motion is detected it winds up,raising the ghost. When the ghost reaches its normal limit of travelupwards the cord opens the switch which then signals the motor controlcircuit but does not stop the motor, which then continues winding untilthe string completely unravels, suddenly. When this happens the switchwill have gone back to its closed state and as it does so the motorcontrol circuit stops the motor. During this phase the ghost is sittingon the floor in its dormant state.

The invention thus provides, in this third aspect, a very neat andsimple way of improving movement effect of ornaments which canrealistically mimic the desired effect of something dropping from aheight and travelling back upwardly, or something slowly rising from thefloor and then suddenly dropping.

It will be understood to those persons skilled in the art that theinvention in its several aspects is illustrative of the simplicity andadaptability of the method by which it may be performed and is notintended to be limited thereby.

What is claimed is:
 1. An ornament mover comprising an ornament movementreciprocation means including a synchronous motor connected to a pulleymechanism having a reaction means for stalling the motor at a point inthe path of reciprocation, wherein the pulley mechanism comprises agearing means powered by the motor to wind a cord to which the ornamentis connected onto a pulley drum to a retracted position, wherein areaction member butts against a casing of the ornament mover causing thesynchronous motor to stall, wherein reaction forces between a rotor anda stator of the motor then cause the motor to reverse direction, thusunwinding the cord from the drum to its fullest extent, at which pointthe pulley drum continues to rotate in the same direction such that thecord is again wound onto the drum but from the opposite rotationaldirection.
 2. An ornament mover comprising a housing, motor meansassociated with the housing, a pulley drum drivingly connected to themotor means, a cord attached at one end to the drum and at its other endto an ornament to be carried thereby, the cord being windable onto thedrum by the motor means, switch means for guidingly receiving the cordand being moveable between a first position in which the cord can bewound onto the drum and a second position in which the cord is movedaxially relative to the rotational axis of the drum so that in suchposition it can become suddenly fully unwound therefrom, and controlcircuit means for determining when the switch means is to move from itsfirst position to its second position, thereby to selectively providewinding and sudden unwinding of the cord and consequent correspondingmovement of an ornament attached thereto.
 3. An ornament mover accordingto claim 2, wherein the control circuit means includes an electroniccircuit coupled to a motion detector such that upon motion beingdetected the motor may be activated to provide for winding of the cord.